static const float4 palette[16] = {
    float4(0x00 * 255 / 63, 0x00 * 255 / 63, 0x00 * 255 / 63, 0xff) / 0xff,
    float4(0x0b * 255 / 63, 0x0b * 255 / 63, 0x26 * 255 / 63, 0xff) / 0xff,
    float4(0x15 * 255 / 63, 0x2b * 255 / 63, 0x13 * 255 / 63, 0xff) / 0xff,
    float4(0x0e * 255 / 63, 0x22 * 255 / 63, 0x21 * 255 / 63, 0xff) / 0xff,
    float4(0x20 * 255 / 63, 0x0c * 255 / 63, 0x0e * 255 / 63, 0xff) / 0xff,
    float4(0x23 * 255 / 63, 0x0f * 255 / 63, 0x26 * 255 / 63, 0xff) / 0xff,
    float4(0x23 * 255 / 63, 0x14 * 255 / 63, 0x0a * 255 / 63, 0xff) / 0xff,
    float4(0x2c * 255 / 63, 0x2c * 255 / 63, 0x2c * 255 / 63, 0xff) / 0xff,
    float4(0x12 * 255 / 63, 0x12 * 255 / 63, 0x12 * 255 / 63, 0xff) / 0xff,
    float4(0x1c * 255 / 63, 0x1b * 255 / 63, 0x3b * 255 / 63, 0xff) / 0xff,
    float4(0x2a * 255 / 63, 0x3f * 255 / 63, 0x28 * 255 / 63, 0xff) / 0xff,
    float4(0x1d * 255 / 63, 0x33 * 255 / 63, 0x32 * 255 / 63, 0xff) / 0xff,
    float4(0x31 * 255 / 63, 0x1b * 255 / 63, 0x1c * 255 / 63, 0xff) / 0xff,
    float4(0x35 * 255 / 63, 0x23 * 255 / 63, 0x38 * 255 / 63, 0xff) / 0xff,
    float4(0x3b * 255 / 63, 0x3c * 255 / 63, 0x1c * 255 / 63, 0xff) / 0xff,
    float4(0x3f * 255 / 63, 0x3f * 255 / 63, 0x3f * 255 / 63, 0xff) / 0xff,
};
